JP2006208897A - Lens system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase continuous shooting speed of a camera to shorten a period of release time lag when any interchangeable lens is attached. <P>SOLUTION: To camera microcomputer 21 performs an operation for accumulating received light intensity in an AF sensor to a ranging unit 22 simultaneously as a ranging operation and the ranging unit 22 outputs detection results to the camera microcomputer 21. The microcomputer 21 determines traveling amount of a focal lens 2 from the results of AF after accumulation by an operation and transmits it to a lens microcomputer 13 with an AF drive starting instruction. The lens microcomputer 13 energizes a stepping motor of a motor unit 14 simultaneously as receiving the AF drive starting instruction and a drive amount to start transfer of a focal unit 11. The drive amount of the motor is detected by a motion detector 16, when the drive amount reaches the one received from the camera microcomputer 21, energization of the motor is stopped and stop information is communicated to the camera microcomputer 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention controls a diaphragm mechanism for adjusting the amount of light incident on the camera body using a drive mechanism such as a stepping motor, and optimally and quickly selects a desired mechanism based on various information transmitted from the camera. The present invention relates to a lens system for setting the amount of light.

  Current cameras are generally equipped with an autofocus (AF) function, and there is a demand for higher accuracy in autofocus and shorter time until the subject is in focus. On the other hand, the diaphragm mechanism is shifting from a conventional mechanical configuration to one driven by a driving source such as a stepping motor or an electromagnetic meter, thereby enabling various controls. ing. Furthermore, it is necessary in the future to shorten the driving time to the set aperture position by changing these control constants and the control sequence and algorithm as the camera system.

  Cameras that use these accelerated autofocus and iris controls can improve the continuous shooting speed, and the continuous shooting speed of this camera is a target for performance comparison with other companies' cameras. There is a need to further improve performance in the future.

  As a measure for improving the continuous shooting speed, in Patent Document 1, once the aperture is driven to an aperture value that can be detected by the focus detection sensor for autofocus, and the aperture is redriven after autofocus, It is described that the driving time can be shortened.

  This is because, for example, when a lens with an open aperture value of F2.8 is narrowed down to F32, seven stages of drive time are required. However, according to the disclosure of Patent Document 1, the aperture value capable of autofocus detection is set to F5.6. Then, it is only necessary to stop the aperture by 2 steps up to F5.6, and drive the remaining 5 steps after autofocusing, so that the time required to drive the aperture is shortened and the continuous shooting speed of the camera is improved. become.

  Japanese Patent Application Laid-Open No. H10-228707 describes that driving time data for the number of driving stages of the aperture is stored in advance in a memory in the camera, and the release sequence of the camera is set to optimal control based on the time data.

JP 2000-162494 A JP 2003-101875 A

  FIG. 6 is an example showing a control method when a stepping motor is used for aperture control, where the horizontal axis is the accumulated time during aperture drive, the vertical axis in (a) is the aperture value, and the vertical axis in (b) is the motor. Each driving speed is shown. (B) shows a general speed control pattern of a stepping motor, which is driven at respective control speeds of acceleration, constant speed, and deceleration.

  In addition, the 1-2 phase excitation method is generally used for motor driving from the viewpoint of the accuracy of stepping motors. However, the stop position becomes unstable when the power is turned off, so the initial state is just before driving. It is necessary to perform initial positioning by energization. In addition, vibration during driving often remains even when stopped, and a stabilization waiting time is required, and the result of adding all these control times is the accumulated time required for aperture driving.

  In FIG. 6A, for example, the relationship between the aperture value and the accumulated time when a lens having an open aperture value of F2.8 is stopped down to F32 is shown. Basically, each of acceleration / deceleration and constant speed in FIG. Reciprocal speed (time). Further, as described above, the stop position of the stepping motor becomes unstable when the power is turned off, and when used in the aperture mechanism, the aperture value when the aperture is set to the open value becomes unstable.

  In order to avoid this, as shown in FIG. 7, the aperture value is usually determined by the inner diameter (open diameter) of a mechanically fixed disk, and the diaphragm blades made up of a plurality of plates by the rotation operation of the stepping motor. The aperture value is determined by taking 1 in and out, and the position where the aperture blade 1 does not protrude beyond the inner diameter of the disk is the initial position of the motor.

  That is, as shown in FIGS. 6 and 7, when the aperture is driven from the open value to the small aperture value, there is a region where the stepping motor is driven but the aperture value does not change at the initial stage of driving. This is because a plurality of aperture blades 1 do not appear unless the motor is driven by a predetermined amount. This section that is driven by a certain amount is called a run-up section, and the time between these is the run-up time.

  In addition, when the aperture stops, the stepping motor itself tries to stop the operation when the aperture stops to F32, which is the small aperture stage number. However, since the aperture mechanical mechanism considers high speed driving, It has been found that the load torque tends to be lightened, so that the balance with the inertial force is deteriorated, and the diaphragm blade 1 for determining the actual light quantity stops while bouncing. The bounds of the diaphragm blades are perceived as fluctuations in the amount of light as they are, so a stabilization waiting time as shown in FIG. 6 is incorporated into the control, and after waiting for the time to elapse, the diaphragm drive is finished for the camera. Communicating.

  FIG. 8 is a time chart showing a general camera exposure operation in a sequential manner. FIG. 8A shows the timing of the operation sequence when the continuous shooting speed (frame speed) of the camera is displayed as a time value. . For example, if the frame speed is 10 frames / second, the Hi area of the frame speed is 1/10 seconds, and all operation sequences must be completed within that time.

  (B) is a photometric operation for detecting the amount of light at or near the subject and calculating the optimum shutter speed and aperture, and (c) is the amount of light applied to the AF sensor for detecting the focus state of the subject simultaneously with this photometry. (D) is a mirror-up operation simultaneously with the end of the accumulation operation, (e) is an AF drive operation for driving the lens and focusing on the subject when the AF calculation ends, (f) Is an exposure operation for performing aperture driving upon completion of the AF accumulation operation, and (g) is an exposure operation that is performed for the first time when all the above operations are completed. With these operations, the sequence until photographing is completed.

  This operation sequence and each operation time are merely examples, and in particular, (c) AF accumulation time, (e) AF drive time, (f) aperture drive time, (g) exposure time are the focus state of the subject, light amount, etc. May change drastically.

  When the patterns of FIGS. 6 and 8 are applied to the previous Patent Document 2, the Patent Document 2 has a leading blade time lag and a leading blade curtain speed at the time of exposure, and the aperture is driven earlier by the driving time. According to this document, the release time lag is shortened. In this case, the time of the leading blade time lag and the leading blade curtain speed can be recognized on the camera side, but the aperture driving time is only described in Patent Document 2 as being stored or calculated in the internal memory. .

  If the lens is integrated with the camera, this method is considered to be safe, but in the case of an interchangeable lens camera, the actual aperture drive time varies depending on the type of interchangeable lens installed. There is also a lens that is generated and whose driving speed varies depending on the power supply voltage applied to the stepping motor. Therefore, since the aperture drive time stored in the camera is the maximum aperture drive time of various lenses, the control method of Patent Document 2 is meaningless when an interchangeable lens with a fast aperture drive time is attached. There is a fear.

  An object of the present invention is to provide a lens system that solves the above-described problems and speeds up the aperture drive in the interchangeable lens.

  The technical feature of the lens system according to the present invention for achieving the above object is that the communication means for communicating with the camera main body and the light quantity information transmitted from the camera main body by the communication means are described above. A light amount control means for controlling the amount of light incident on the camera body, a control time determination means for determining a control time of the light amount control means based on data other than the light quantity information transmitted from the camera by the communication means, When the light quantity control means starts the control, the time measurement means measures the time, and when the time information output from the time measurement means is equal to or greater than the control time determined by the control time determination means, the light quantity control means A light amount control end transmitting means for transmitting to the camera main body that the light amount control has ended irrespective of the state.

  According to the lens system of the present invention, the aperture mechanism can be sped up regardless of which interchangeable lens is attached, and the continuous shooting speed of the camera can be greatly improved as compared with the prior art. It becomes possible to respond.

  The present invention will be described in detail based on the embodiment shown in FIGS.

  FIG. 1 is a block diagram of an autofocus single-lens reflex camera and an interchangeable lens unit. This lens system is roughly divided into an autofocus interchangeable lens unit 10 and a camera body unit 20. In addition, the solid line arrow of FIG. 1 means electrical connection, a dotted line means mechanical connection, and a dashed-dotted line represents the optical axis.

  In the interchangeable lens unit 10, a focus unit 11 having an optical lens for focusing on a subject and an aperture mechanism 12 for changing the amount of light are arranged. Furthermore, a lens microcomputer 13 that controls all of the interchangeable lens unit 10 is provided in the interchangeable lens unit 10. The lens microcomputer 13 drives a motor unit 14 that drives the focus unit 11 with a stepping motor and an aperture mechanism 12. A diaphragm unit 15 that performs the operation, a motion detector 16 that detects the operation of the motor unit 14, and an EEPROM 17 that stores information relating to the interchangeable lens unit 10.

  The camera main body 20 is provided with a camera microcomputer 21 for controlling all of the cameras, and a built-in autofocus distance measuring unit 22 and exposure metering unit 23 are connected. 21 is connected to the lens microcomputer 13 of the interchangeable lens unit 10 via a contact unit 24.

  The focus unit 11 includes a mechanism that holds the optical lens and moves in the optical axis direction, and the motor unit 14 transmits a motor that is a drive source for moving the focus unit 11 in the optical axis direction and the driving force of the motor. Including a plurality of gear trains.

  The lens microcomputer 13 has functions such as a general-purpose I / O port, a serial communication function, a timer counter function, an A / D function, a D / A function, and a plurality of interrupt input functions using external terminals. The aperture unit 15 includes a stepping motor that is a drive source for operating the aperture mechanism 12 and a speed reduction mechanism thereof.

  The motion detector 16 is connected to a part of the gear in the focus unit 11 with a circular plate called a pulse plate whose periphery is magnetized, and the pulse plate rotates in accordance with the rotation of the motor. An element called an element reads and outputs the strength of the magnetic field, and the lens microcomputer 13 reads the pulse output generated through the detection circuit. This pulse output is equal to the moving amount of the focus unit 11, and the moving speed of the focus unit 11 can also be detected by reading the pulse period. In addition to the MR element, the motion detector 16 may be of a type that detects an optical signal such as a photo interrupter or a photo reflector by converting it into an electrical signal.

  The EEPROM 17 is used, for example, when adjusting the control constant of the focus unit, the control constant of the aperture mechanism, or the like.

  The camera microcomputer 21 is configured to determine the amount of movement of the focus unit 11 from the communication with the lens microcomputer 13 and the output value from the distance measuring unit 22. The distance measuring unit 22 on the camera body 20 side is configured to detect the amount of defocus to the subject, and this method is, for example, a phase difference detection method that is the mainstream of current autofocus. The photometric unit 23 detects the amount of light from the subject, and the camera microcomputer 21 determines the shutter speed and the lens aperture value from the detected values.

  The contact unit 24 has a plurality of metal protrusions on the camera body 20 side, and a metal piece is embedded on the interchangeable lens part 10 side so as to contact the protrusions. A power supply terminal, a GND terminal, a communication input terminal, a communication output terminal, a synchronous clock terminal, and the like are connected to the protrusion on the camera body 20 side. When the interchangeable lens section 10 is attached to the camera body 20, the interchangeable lens section The lens microcomputer 13 receives communication and power supply between the camera body 20 and the lens body 10 through synchronous serial communication through the contact point.

  Further, the camera body 20 is provided with a switch (not shown). The switch has a specification that the operation of the camera body 20 is different depending on whether it is pressed or not. For example, S1 is when pressed lightly, and S2 is when pressed strongly. S1 is an operation for AF and photometry only, and S2 further includes a release operation.

  When this switch is operated by the user, the camera microcomputer 21 operates the distance measuring unit 22 and the photometric unit 23. The distance measuring unit 22 performs an operation of accumulating the amount of light received by the internal AF sensor in order to focus on the subject. When the accumulation is completed, the distance measuring unit 22 outputs the detection result to the camera microcomputer 21. The camera microcomputer 21 calculates the shift amount of the subject image from the detection result of the distance measuring unit 22 and calculates the movement amount of the focus unit 11.

  Lens information necessary for calculations such as sensitivity information, AF deviation between the AF sensor and the film or CCD surface, and the amount of movement of the focus unit 11 with respect to the minimum drive amount in the motion detector 16 is obtained from the lens microcomputer 13 in advance by the contact unit 24. Communicate through and store in internal memory.

  The photometry unit 23 detects the reflected light from the subject and outputs it to the camera microcomputer 21. The camera microcomputer 21 calculates and determines an appropriate aperture value and shutter speed according to the shooting mode of the current camera such as continuous shooting, single shooting, portrait, and sports.

  Further, when the switch state is S2, the camera microcomputer 21 calculates aperture value data of the aperture based on the photometric detection data when the calculation process after photometric detection and the accumulation of the AF sensor are completed. Along with the delay time data during the release process such as the leading blade time lag time and the leading blade curtain speed time, which is the time of the hatched portion of the exposure timing in FIG. Send a start command. Time information such as the leading blade time lag time and leading blade curtain speed time at this time is stored in advance in the internal memory of the camera microcomputer 21. In addition to the above-described time information, these time information may actually be a delay time caused by a sequence until the exposure is started.

  When the accumulation of the AF sensor is completed, the camera microcomputer 21 performs a mirror up operation, an exposure operation, an AF driving start process of the interchangeable lens unit 10, and a mirror down operation. When the exposure is completed, film winding operation or the like is performed in the case of a silver lead camera, and image processing, display processing, transfer operation to an external memory, or the like is performed in the case of a digital camera.

  When the interchangeable lens unit 10 is attached to the camera main body unit 20, the lens microcomputer 13 is initialized first, and then each unit inside the interchangeable lens unit 10 is initialized. The lens microcomputer 13 communicates that the initialization is completed to the camera microcomputer 21 through the contact unit 24 based on status information indicating the state of the interchangeable lens unit 10. When the switch is operated by the user as described above, the camera microcomputer 21 communicates a transmission request for various information related to AF to the lens microcomputer 13, and the lens microcomputer 13 reads the information from the memory of the EEPROM 17, etc. To 21.

  Next, when the camera microcomputer 21 detects the state of the switch and detects that it is in the state of S2, the distance measuring unit 22 and the photometric unit 23 are operated. The photometry unit 23 detects the reflected light from the subject and outputs it to the camera microcomputer 21. When the photometric operation is completed, the camera microcomputer 21 calculates and determines an appropriate aperture value and shutter speed in accordance with the current shooting mode of the camera such as continuous shooting, single shooting, portrait, and sports.

  From the calculation result, the camera microcomputer 21 transmits the delay time information at the time of the exposure operation to the lens microcomputer 13 simultaneously with the driving start command of the aperture mechanism 12. When the lens microcomputer 13 receives this command, it starts energizing the stepping motor in the aperture unit 15.

  Next, the lens microcomputer 13 detects the voltage of the contact pin for the power source supplied from the contact unit 24, and the rotation speed of the stepping motor is determined from a plurality of speed information stored in advance in the internal memory from the detection result. Decide and control the speed of the stepping motor at that speed.

  When the voltage supplied from the camera body 20 is low, the voltage applied to the aperture stepping motor is also low. When the stepping motor is rotated at a high speed while the voltage is low, the rotation phase of the motor is electrically Since a so-called step-out phenomenon in which the energization phase is shifted occurs, voltage detection is required.

  When this step-out phenomenon occurs, the stop position of the diaphragm is shifted. In order to prevent this, the voltage is detected, and control is performed so that the step-out phenomenon does not occur. After determining the rotational speed, the lens microcomputer 13 calculates when it is necessary to transmit a driving end command for the aperture mechanism 12 to the camera microcomputer 21.

  As this calculation method, first, the aperture drive time is calculated from the aperture speed information and the drive amount information received from the camera microcomputer 21, and the exposure operation delay time received from the camera microcomputer 21 is calculated from the drive time. It can be calculated by subtracting. This is an operation sequence in which the aperture driving is actually performed, but the fact that the aperture driving is completed is communicated to the camera microcomputer 21, and the camera microcomputer 21 receives this communication and starts the exposure operation.

  At this time, since the camera body 20 has a delay time until the actual exposure operation starts even after shifting to the exposure operation, the delay time is equal to the remaining aperture drive time, and the actual aperture drive is completed. At the same time, the actual exposure operation of the camera body 20 is started, so that the time can be reduced as the exposure sequence.

  The lens microcomputer 13 starts driving the aperture unit 15 and simultaneously starts an internal timer to measure the time. The time obtained by subtracting the exposure delay time of the camera body 20 from the drive time of the aperture mechanism 12 is compared with the current timer value. If the timer value is the same or larger, the aperture of the aperture mechanism 12 is driven by the camera microcomputer 21. Communicate end information. Thereby, the camera body 20 starts a series of exposure operations. Since the actual exposure operation is started at the same time as the driving of the aperture unit 15 is completed, there is no change in the photographed image, and the time of the exposure sequence is shortened.

  Next, simultaneously with the photometry operation, the camera microcomputer 21 performs an operation of accumulating the received light amount in the internal AF sensor in order to focus the subject on the distance measurement unit 22. When the accumulation ends, the detection result is output to the camera microcomputer 21. The camera microcomputer 21 determines the movement amount of the focus lens 2 from the result after the AF is accumulated, and transmits it to the lens microcomputer 13 together with the AF drive start command.

  The lens microcomputer 13 energizes the stepping motor of the motor unit 14 simultaneously with receiving the AF driving start command and the driving amount, and starts moving the focus unit 11. The lens microcomputer 13 detects the drive amount of the motor by the operation detector 16, and when the drive amount received from the camera microcomputer 21 is reached, the energization of the motor in the motor unit 14 is stopped, and the camera microcomputer 21 stops the focus unit 11. Communicate information.

  As described above, the exposure sequence is shortened by adopting the first embodiment. For example, the driving amount of the aperture unit 15 is increased, and the frame speed time of FIG. 8 is shortened. Since the frame speed can be expected to increase, it is possible to present faster camera specifications for the user.

  FIG. 2 is a flowchart showing processing of the camera microcomputer 21. As a precondition of the present embodiment, each operation timing is the same as that in FIG.

  [Steps S100, S101]: The camera body 20 is usually equipped with a release button (not shown), and the user prompts the camera body 20 to operate with the release button. The release button is a two-stage stroke switch that is set to AF operation when the first stage, that is, only one stroke is on, and AF operation and release operation when the second stage is on. It is common. Hereinafter, the ON in one stroke is S1, and the ON in the first stroke is S2 (which naturally includes S1).

  First, the camera microcomputer 21 determines whether the user has turned on the release button for only S1. If nothing is pressed, the process waits until it is pressed, and if it is pressed, the process proceeds to step S102.

  [Step S <b> 102]: Since S <b> 1 is pressed, the camera microcomputer 21 transmits various data transmission request commands related to the AF calculation to the lens microcomputer 13. When the lens microcomputer 13 receives this command, it transmits necessary data to the camera microcomputer 21 immediately. The camera microcomputer 21 stores the received lens data in an internal memory. Data necessary for the AF calculation includes status information of the interchangeable lens unit 10, sensitivity information, an AF sensor and film or CCD surface displacement amount, a movement amount of the focus unit 11 with respect to a minimum drive amount in the motion detector 16, and the like. .

  Next, the camera microcomputer 21 outputs a ranging start command to the ranging unit 22, and the ranging unit 22 accumulates the amount of light incident on the AF sensor in the AF CCD. At the same time, the camera microcomputer 21 issues a photometric start command to the photometric unit 23, and the photometric unit 23 detects the amount of light incident on the photometric sensor.

  [Step S103]: The camera microcomputer 21 detects the state of a release button (not shown) and detects whether S2 is on. If S2 is on, the process proceeds to step S104, and if it is off, the process proceeds to step S107.

  [Step S104]: The camera microcomputer 21 waits until the photometry of the photometry unit 23 and the accumulation of AF are completed.

  [Step S105]: Upon completion of photometry, the photometry unit 23 transfers the detected light amount data to the camera microcomputer 21, and the camera microcomputer 21 calculates the optimum shutter speed and aperture value from the values. At this time, the calculation result and a delay time such as a mechanical delay time or a sequence in the exposure operation of the camera body 20 are transmitted to the lens microcomputer 13.

  [Step S106]: In preparation for exposure start, the camera microcomputer 21 starts up the mirror positioned in front of the shutter.

  [Step S107]: In step S103, the camera microcomputer 21 detects the state of the release button. If S2 is OFF, the process directly proceeds to step S107, and this step is also performed after the mirror up operation is started in step S106. Migrate to In step S104, the camera microcomputer 21 receives the accumulation result of the AF sensor, and determines whether or not the subject is in focus. Since it is not necessary to move the focus unit 11 in the in-focus state, the process proceeds to step S110. If the subject is not in focus, the process proceeds to step S108.

  [Step S108]: If the subject is not in focus, the camera microcomputer 21 transmits the movement amount of the focus unit 11 and a correction start command to the lens microcomputer 13.

  [Step S109]: The camera microcomputer 21 communicates a status information transmission request to the lens microcomputer 13 in order to detect the state of the interchangeable lens unit 10. When the movement of the focus unit 11 is completed, the lens microcomputer 13 communicates with the camera microcomputer 21 that the correction has been completed using the status information of the interchangeable lens unit 10. The camera microcomputer 21 waits until the movement of the focus unit 11 is completed.

  [Step S110]: The camera microcomputer 21 detects the state of the release button and detects whether S2 is on. When S2 is on, the process proceeds to step S111, and when it is off, the process proceeds to step S101.

  [Step S111]: The camera microcomputer 21 starts mirror-up at step S106. The camera microcomputer 21 determines whether or not this mirror-up drive has ended. If not, the camera microcomputer 21 waits for the end.

  [Step S112]: The camera microcomputer 21 starts driving the aperture mechanism 12 in step S105. The camera microcomputer 21 communicates a status information transmission request of the interchangeable lens unit 10 to the lens microcomputer 13 to determine whether the aperture mechanism 12 has been driven. . At this time, the lens microcomputer 13 replaces the camera microcomputer 21 with the fact that the driving of the aperture mechanism 12 has been completed in consideration of the delay time of the exposure operation received in step S105 even if the actual aperture driving has not ended. Communication is performed using the status information of the lens unit 10. The camera microcomputer 21 waits for this end.

  [Step S113]: Since all the controls described above have been completed, the camera microcomputer 21 starts a shutter operation and starts exposure to the CCD. At this time, a mechanical or sequence delay time occurs in the exposure operation, and actual exposure to the film or the CCD is started only after the time has elapsed. At the start of this actual exposure, the actual driving of the aperture unit 15 ends, and the exposure sequence time corresponding to this time is shortened.

  [Step S114]: The camera microcomputer 21 waits until the exposure is completed.

  [Step S115]: Since the exposure of the camera microcomputer 21 is completed, the camera microcomputer 21 drives the mirror in the downward direction, and all the drive processing of the interchangeable lens unit 10 including the mirror drive is completed, that is, until the status information of the interchangeable lens unit 10 changes. wait. In addition, the processing of the image data exposed during the waiting and the transfer to the external or internal memory are performed, and if all of them are completed, the process proceeds to step S101.

  The processing up to the exposure of the camera body 20 is as described above, and the camera body 20 repeats again from step S101 in the continuous shooting mode.

  FIG. 3 is a flowchart relating to the communication interruption process of the lens microcomputer 13.

  [Step S200]: First, the camera microcomputer 21 and the lens microcomputer 13 are designed to perform bidirectional communication. When communication is transmitted from the camera microcomputer 21, the lens microcomputer 13 executes this interrupt process. The lens microcomputer 13 immediately analyzes the command transmitted from the camera microcomputer 21 and determines the next operation. The command is code data representing the request contents from the camera microcomputer 21 to the lens microcomputer 13, and the code data and communication contents are determined in advance by the camera body 20 and the interchangeable lens section 10 to establish mutual communication. It is a specification.

  The lens microcomputer 13 analyzes the command that is the code data and determines a request from the camera. Examples of command contents include a movement command for the focus unit 11, a movement amount reception request, a movement stop command, a drive permission command for the aperture mechanism 12, a driving amount reception request, a focal length, sensitivity, AF error information, FNo, lens status information, and the like. The lens microcomputer 13 analyzes the command data and stores the information transmitted from the camera microcomputer 21 in the next communication in the internal memory as the received data in the next communication after analyzing the command data. As a result of the analysis, in the case of a transmission request, the data required by the camera microcomputer 21 is transmitted to the camera microcomputer 21. It has become.

  [Step S201]: The lens microcomputer 13 analyzes the command from the camera microcomputer 21, and determines whether or not it is a movement permission command for the focus unit 11.

  [Step S202]: If the result of command analysis in Step S201 is a movement permission command for the focus unit 11, the motor in the motor unit 14 is energized in order to move the focus unit 11 immediately. The driving force is transmitted and the focus unit 11 is moved. Further, the status information storage memory in the lens microcomputer 13 stores that AF driving is in progress.

  [Step S203]: The lens microcomputer 13 analyzes the command from the camera microcomputer 21, and determines whether or not it is an aperture drive permission command.

  [Step S204]: If the result of command analysis in Step S203 is an aperture drive permission command, the lens microcomputer 13 reads the voltage supplied from the contact unit 24 with an internal A / D conversion function, and the read data Then, the aperture driving speed is determined and stored in the internal memory.

  Further, the aperture driving time is calculated from the determined driving speed and the aperture driving amount previously received from the camera microcomputer 21, and the result obtained by subtracting the exposure delay time previously received from the camera microcomputer 21 from the calculation result is stored in the internal memory. Remember. Next, in order to drive the aperture mechanism 12, the stepping motor in the aperture unit 15 is energized. When the rotation of the stepping motor starts, the driving force is transmitted by the gear train, and the aperture mechanism 12 is driven. The status information in the internal memory stores that the aperture is being driven.

  [Step S205]: The lens microcomputer 13 once clears the timer in the microcomputer and starts counting at a predetermined time timing.

  [Steps S206 and S207]: The lens microcomputer 13 analyzes the received command to determine whether it is a transmission request or a reception request for various data from the camera microcomputer 21, and in the case of a transmission request, transmits data corresponding to the command. To do. At this time, when the command data received from the camera microcomputer 21 is the status information of the interchangeable lens unit 10, the lens microcomputer 13 is currently moving or stopping the focus unit 11 and driving or stopping the aperture mechanism 12. Is transmitted as status information to the camera microcomputer 21. The camera microcomputer 21 confirms the state of the interchangeable lens unit 10 with this status information and determines the next sequence.

  Further, when the command received from the camera microcomputer 21 is analyzed and the reception request is for various data, the lens microcomputer 13 receives the information from the camera microcomputer 21 in the next communication, and stores the data according to the contents in the internal memory. To remember. Note that examples of transmission data and reception data are as described in step S200.

  [Step S208]: When the command analysis by communication from the camera microcomputer 21, the data setting, and the transmission process are completed, the interrupt process is terminated.

  FIG. 4 is a flowchart of a program relating to various controls of the lens microcomputer 13 of the first embodiment.

  [Steps S300 and 301]: When the interchangeable lens unit 10 is attached to the camera body 20, power is supplied to the lens microcomputer 13 through the contact unit 24, and the lens microcomputer 13 executes a reset process. In this reset processing, initialization of the internal memory, prohibition of energization of each unit, initialization, and the like are performed. When each processing is completed, the fact that the initialization is completed is recorded in the status information and transmitted to the camera microcomputer 21.

  Further, the state of the switches attached to the interchangeable lens unit 10 is detected and stored in the internal memory. The switches include, for example, a switch for switching between two operation modes of auto focus and manual focus, zoom position information, position information of the focus unit 11, and the like.

  [Step S302]: First, the lens microcomputer 13 determines from the status information in the internal memory whether or not the focus unit 11 is moving.

  [Step S303]: When the focus unit 11 is moving in step S302, it is determined whether or not the drive amount received in advance from the camera microcomputer 21 is equal to the drive amount detected by the motion detector 16. This drive amount becomes equal, indicating that the focus unit 11 has reached a predetermined position.

  [Step S304]: When the focus unit 11 has not reached the predetermined position, the lens microcomputer 13 detects the cycle of the pulse output output from the operation detector 16, and the focus unit 11 is set to a predetermined speed set in advance. It is determined whether it has reached or is not too early, and the energization voltage to the motor in the motor unit 14 is varied according to each case, and control is performed so as to reach a predetermined speed.

  [Step S305]: When the focus unit 11 is stopped in step S302 and when the process of step S304 is completed, the lens microcomputer 13 determines whether or not the aperture mechanism 12 is being driven. If not, the process proceeds to step S301.

  [Step S306]: If the aperture mechanism 12 is being driven in step S305, it is determined whether the drive amount received from the camera microcomputer 21 is equal to the control drive amount. This equal amount of drive indicates that the aperture mechanism 12 has reached a predetermined position. If the drive amounts are not equal, the process proceeds to step S307, and if the drive amounts are equal, the process proceeds to step S310.

  [Step S307]: The lens microcomputer 13 determines whether to switch the energization pattern to the stepping motor in the aperture unit 15 when the aperture mechanism 12 has not reached the predetermined position, that is, when the drive amount is insufficient. The driving principle of the stepping motor is a method in which the rotational force is generated by switching the energization of the two-phase electromagnetic coils out of phase with a specific pattern over time, so the time for switching the pattern has elapsed. Judgment.

  Since the number of times this pattern is switched is the same as the drive amount of the aperture mechanism 12, when the aperture mechanism 12 is being driven, the cumulative number of times this pattern is switched is stored, and the result is used as the drive amount. . Further, the rotation speed of the stepping motor is determined by a time interval for switching the energization pattern. The lens microcomputer 13 detects the passage of time with an internal timer, and performs a process of switching the energization pattern when it has elapsed. If the time has not elapsed, nothing is done and the process proceeds to step S308.

  At this time, the timer value started in step S205 in FIG. 3 is compared with the contents of the memory storing the time value for determining the end of driving of the diaphragm in step S204. If the timer value is the same or larger, Assuming that the driving of the mechanism 12 has been completed, it is stored in the status information of the internal memory of the lens microcomputer 13 that the aperture driving is being stopped. The camera microcomputer 21 detects that the aperture driving is stopped and starts the exposure operation.

  [Step S308]: The energization voltage to the motor in the motor unit 14 is varied and controlled so as to have a predetermined speed.

  [Step S309]: When it is determined in Step S303 that the position of the focus unit 11 has reached the predetermined position, that is, the drive amount has become equal to the predetermined drive amount, the energization of the motor in the motor unit 14 is stopped, and the focus unit 11 The moving process is terminated. At this time, the fact that the AF drive is stopped is stored in the status information of the internal memory, and the process proceeds to step S301.

  [Step S310]: When it is determined in step S306 that the position of the aperture mechanism 12 has reached the predetermined position, the power supply to the stepping motor in the aperture unit 15 is stopped, and the drive process of the aperture mechanism 12 is terminated. At this time, the fact that the aperture driving is stopped is stored in the status information of the internal memory, and the process proceeds to step S301. Although there is a possibility that it is already stopped in step S307, there is no problem in sequence even if the same operation is performed.

  From the above contents, the delay information in the exposure operation of the camera is transmitted from the camera body 20 to the interchangeable lens unit 10, and the interchangeable lens unit 10 takes into consideration the fluctuating driving time of the aperture and the delay information, and the camera microcomputer By manipulating the status information for 21, the exposure sequence becomes faster.

  In the first embodiment, the exposure sequence considering the delay time at the time of exposure of the camera microcomputer 21 has been described. However, when the performance of the shutter mechanism on the camera body 20 side is further improved, this delay time will be described. There is a high possibility that the amount will be insignificant. Accordingly, paying attention to the sequence on the interchangeable lens unit 10 side, the second embodiment particularly improves the stabilization waiting time shown in FIG.

  FIG. 5 is a time chart of the camera operation sequence of the second embodiment. When the interchangeable lens unit 10 is mounted on the camera body 20, the lens microcomputer 13 is initialized first, and the lens microcomputer 13 is replaced after initialization. Each unit in the lens unit 10 is initialized. The lens microcomputer 13 communicates that the initialization has been completed to the camera microcomputer 21 through the contact unit 24 with status information indicating the state of the lens. When the switch is operated by the user, the camera microcomputer 21 communicates a transmission request for various information regarding AF to the lens microcomputer 13, and the lens microcomputer 13 reads the information from the memory of the EEPROM 17 and transmits it to the camera microcomputer 21. .

  Further, when the switch state is S2, the camera microcomputer 21 determines the aperture based on the photometric detection data when the calculation processing after the photometric detection in (b) and the accumulation of the AF sensor in (c) are completed. The aperture value data of the mechanism 12 is calculated. Next, the aperture value data calculated together with the shutter speed value such as 1/500 second or 1/1000 second previously calculated and the operation start command of the aperture mechanism 12 are transmitted to the lens microcomputer 13.

  The shutter speed value at this time may be a case where the camera microcomputer 21 automatically calculates from the output value of the photometry unit 23, or a case where the camera user sets the shutter speed priority mode and decides on his own.

  When the accumulation of the AF sensor in (c) is completed, the camera microcomputer 21 performs the mirror up operation and exposure operation in (d), the AF driving start process of the interchangeable lens unit 10, and the mirror down operation. When the exposure is completed, film winding operation or the like is performed in the case of a silver lead camera, and image processing, display processing, transfer operation to an external memory, or the like is performed in the case of a digital camera.

  Upon completion of the photometric operation in (b), the camera microcomputer 21 calculates and determines an appropriate aperture value and shutter speed according to the current camera's shooting mode such as continuous shooting, single shooting, portrait, or sports. . From the calculation result, the camera microcomputer 21 transmits shutter speed information to the lens microcomputer 13 simultaneously with the driving start command for the aperture mechanism 12.

  When the lens microcomputer 13 receives this command, it starts energizing the stepping motor in the aperture unit 15. The lens microcomputer 13 detects the voltage of the contact pin for power supplied from the contact unit 24, determines the rotation speed of the stepping motor from a plurality of speed information stored in the internal memory in advance from the detection result, The speed of the stepping motor is controlled at this speed. This voltage detection uses an A / D conversion function in the lens microcomputer 13.

  The lens microcomputer 13 analyzes the shutter speed data received from the camera microcomputer 21 and compares it with a preset threshold value. If the camera is set to a shutter speed slower than this threshold value, the aperture drive is completed for the camera microcomputer 21 without waiting for the aperture stabilization wait time, which is the shaded area of the aperture drive in FIG. Send the status information. This is a control method that assumes that the influence of a slight aperture value error is reduced when the actual captured image is viewed when the shutter speed is slow.

  As shown in FIG. 6, it is known that the diaphragm blades bounce at the stable stabilization waiting time, and the amount of light reaching the camera body 20 side also fluctuates. However, on average, F32 is maintained as the aperture value. Can be judged. That is, when the shutter speed is high, the time for averaging is shortened and may appear in the captured image. However, when the shutter speed is low, there is no problem.

  Further, if the shutter is released within the stabilization waiting time shown in FIG. 5F, that is, when the exposure operation is completed, the image is shot with the aperture operation being unstable. If the shutter operation is terminated at the same time as the stabilization waiting time has elapsed, an image with the light intensity averaged is taken as described above. Therefore, the threshold is set so that the stabilization waiting time of the aperture is equal to the shutter speed. If so, there is no problem.

  Since the aperture stabilization waiting time is finely set according to the configuration of the aperture mechanism 12 in the interchangeable lens unit 10 and the motor speed in the aperture unit 15, the lens microcomputer 13 receives the shutter speed information from the camera microcomputer 21 and the lens. This can be determined by making the above-described determination from both the stabilization waiting time of the diaphragm mechanism 12 set by the microcomputer 13.

  For example, when the shutter speed is set to 1/1000, the time value is 1 msec. Therefore, if the aperture stabilization waiting time is within 1 msec, it is faster than or equal to the shutter speed. It is considered that the change in the amount of light due to the fluctuation is averaged, ignoring the stabilization time of the diaphragm, communicating that the driving of the diaphragm mechanism 12 is completed to the camera microcomputer 21, and as shown in FIG. No. 21 starts the exposure operation by the communication, so that the exposure sequence can be made faster than the conventional exposure operation shown in FIG.

  Next, the camera microcomputer 21 performs an operation of accumulating the amount of light received by the internal AF sensor in order to focus the subject on the distance measuring unit 22 simultaneously with the photometry operation. To 21. The camera microcomputer 21 determines the movement amount of the focus lens 2 from the result after the AF is accumulated, and transmits it to the lens microcomputer 13 together with an AF drive start command.

  The lens microcomputer 13 receives the AF drive start command and the drive amount, and at the same time energizes the motor in the motor unit 14 to start the movement of the focus unit 11. The lens microcomputer 13 detects the driving amount of the motor by the operation detector 16. When the driving amount received from the camera microcomputer 21 is reached, the lens microcomputer 13 stops energization of the motor in the motor unit 14, and the camera microcomputer 21 stops the focus unit 11 stop information. Communicate.

  As described above, in the second embodiment, the exposure sequence is shortened. For example, the driving amount of the aperture unit 15 is increased, and the frame speed time of FIG. 5A is shortened. Since the frame speed can be expected to increase, a higher-speed camera specification can be obtained for the user.

  The operation of the second embodiment is substantially the same as the operation in the flowcharts of FIGS.

  From the above contents, according to the set shutter speed information, the information is transmitted to the interchangeable lens unit 10, and the interchangeable lens unit 10 considers the fluctuating waiting time of the own aperture and the shutter speed information, and the status information. By operating the, the exposure sequence becomes faster.

  In the second embodiment, the exposure sequence considering the shutter speed information of the camera has been described. However, when the shutter speed information on the camera body 20 side is abnormally long, the shutter speed information is purposely transmitted to the interchangeable lens unit 10 side. It is not necessary to make a determination on the interchangeable lens unit 10 side, and it is considered that the processing on the interchangeable lens unit 10 side is faster when simply transmitting to the interchangeable lens unit 10 whether or not taking into account the stabilization waiting time of the aperture. It is done. The third embodiment pays attention to this, and further improvements are added.

  Further, when the switch state is S2, the camera microcomputer 21 calculates aperture value data of the aperture based on the photometric detection data when the calculation process after photometric detection and the accumulation of the AF sensor are completed. Next, the lens microcomputer 13 determines whether the control includes or does not include the stop stabilization waiting time, and sends specific command data. The command data is 1-byte data and may be in the range of numerical value 0 to 255 as long as it can be determined on the interchangeable lens unit 10 side.

  In advance, the camera's main unit 20 stores in the internal memory the maximum aperture stabilization waiting time of all the interchangeable lens units 10, and includes the aperture waiting time by comparing the time information with the shutter speed information. Can be determined. For example, in the case where the maximum diaphragm stabilization wait time of all the interchangeable lens units 10 is 20 milliseconds, if the shutter speed is slower than 1/50, it is determined that the diaphragm stabilization wait time is not included, and the interchangeable lens is not included. What is necessary is just to transmit to the part 10 as command data.

  On the other hand, the lens microcomputer 13 determines from the command data received from the camera microcomputer 21 whether or not the diaphragm stabilization wait time is included, and if the control does not include the diaphragm stabilization wait time, the drive amount is The part that manipulates status information when the predetermined amount is reached ignores the diaphragm stabilization time and communicates to the camera microcomputer 21 that the driving of the diaphragm mechanism 12 has been completed. By starting the operation, the exposure sequence can be accelerated.

  The flowcharts of FIGS. 2, 3 and 4 are the same in the third embodiment, and the method of determining whether the diaphragm stabilization waiting time is in the driving state or the non-driving state is the command data of the camera. It just replaces the content to be judged.

  The preferred embodiments 1 to 3 of the present invention have been described above. However, these embodiments 1 to 3 are effective even with only one embodiment, and when all three embodiments 1 to 3 are combined, the effect is even greater. It is natural to become. Needless to say, the present invention is not limited to these examples, and various modifications and changes can be made within the scope of the invention.

It is a block block diagram of a camera main-body part and an interchangeable lens. It is an operation | movement flowchart figure of a camera microcomputer. It is an operation | movement flowchart figure of the communication interruption process of a lens microcomputer. It is an operation flowchart figure of various control of a lens microcomputer. FIG. 10 is a time chart diagram in the camera operation sequence of Embodiment 2. It is explanatory drawing of the control system of a stepping motor. It is explanatory drawing of an aperture mechanism. It is a time chart figure in the operation sequence of a camera.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Interchangeable lens part 11 Focus unit 12 Aperture mechanism 13 Lens microcomputer 14 Motor unit 15 Aperture unit 16 Operation | movement detector 17 EEPROM
20 Camera Body 21 Camera Microcomputer 22 Distance Measuring Unit 23 Photometric Unit 24 Contact Unit

Claims (5)

  A communication means for communicating with the camera body, a light quantity control means for controlling the amount of light incident on the camera body based on the light quantity information transmitted from the camera body by the communication means, and the communication means. A control time determining means for determining a control time of the light quantity control means based on data other than the light quantity information transmitted from the camera; a timing means for timing the time at the same time when the light quantity control means starts control; and When the time information output from the means is equal to or greater than the control time determined by the control time determining means, the fact that the light quantity control is completed is transmitted to the camera body regardless of the state of the light quantity control means. A lens system comprising: a light amount control end transmission means for the purpose.   The data other than the light amount information transmitted from the camera main body by the communication means is delay time information from the exposure start timing of the camera main body to the actual start of exposure. The lens system described.   The lens system according to claim 1, wherein the data other than the light amount information transmitted from the camera body by the communication unit is exposure time information of the camera body.   The lens system according to claim 1, wherein the data other than the light amount information transmitted from the camera main body by the communication unit is information relating to a control method of the light amount control unit.   5. The lens system according to claim 4, wherein the information related to the control method of the light quantity control means is control time information.

Images